How unusual is this current warm spell?

Our high temperature of 78 degrees Farenheit on March 14 set the all-time record for the date and established a new record for the first 78-degree F temperature of the year, breaking the standing record of March 23, 1910 — over a century ago.

The fact that daily records have not been broken every day during this warm spell testifies to the fact that such warm mid-March days are not unprecedented in Madison’s weather history. One of the unusual aspects of this particular spell of warmth, however, is the prolonged nature of it. Based upon departures from normal (normal being the 30-year average from 1981-2010), this warm spell really began on March 10 when our present streak of days with daily temperatures at least 10 degrees above normal began. It is likely that the streak will not end at least for the next seven or more days, so it will end up being nearly two weeks long.

As warm as it has been, coming so close to 80 degrees last Wednesday made us wonder when Madison’s earliest day at 80 degrees occurred. Turns out this warm spell provided a record in that category, too.

On March 15, Dane County Regional Airport, the official reporting station for Madison, recorded a high temperature of 82 degrees Farenheit — breaking the record for all-time earliest 80-degree day by two full weeks.

Prior to last week, the record was March 29 when, in 1986, the high temperature for the day was 82 degrees Farenheit (the monthly record also recorded on March 31, 1981).

Prior to last week, only five times in the last 43 years had the temperature made it to 80 F in Madison during March (1978, 1981, 1986, 1991 and 2010). In none of those cases did the warm temperatures last nearly two weeks without interruption. Thus, we are in the midst of a truly unusual warm spell.